Purity: Burial at Sea to Prevent Desecration
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 606:
If there is a danger that an enemy will dig up the grave of a deceased person, exhume the body, and cut off its ears, nose, or some other part, then in the event that it is possible to do so, the body must be thrown into the sea in the way mentioned in the previous ruling.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)